16812-18-3Relevant academic research and scientific papers
The kinetics of thiyl radical-induced reactions of monounsaturated fatty acid esters
Chatgilialoglu, Chryssostomos,Altieri, Alessio,Fischer, Hanns
, p. 12816 - 12823 (2007/10/03)
The time-dependent isomerizations and thiol additions of several Z- and E-monounsaturated fatty acid methyl esters catalyzed by alkanethiyl radicals during γ-radiolysis of tert-butyl alcohol solutions are analyzed on the basis of the radiation chemical yield of radicals and established rate data. This provides room-temperature rate constants for the reversible thiyl addition. Within experimental errors, they do not depend on the double bond position in the alkyl chains. Particularly noteworthy is the very fast β-elimination of thiyl radicals from alkyl radicals which carry a second β-substituent. It is supported by additional evidence obtained with a radical clock methodology, and the large preference of fragmentation to the E-isomers is attributed to different barriers for the formation of the E- and Z-transition states from the equilibrium radical structure.
cis-trans Isomerization of monounsaturated fatty acid residues in phospholipids by thiyl radicals
Chatgilialoglu, Chryssostomos,Ferreri, Carla,Ballestri, Marco,Mulazzani, Quinto G.,Landi, Laura
, p. 4593 - 4601 (2007/10/03)
Thiyl radicals reversibly attack the double bonds of methyl oleate and dioleoyl phosphatidyl choline (DOPC), thus producing methyl elaidate and the corresponding phospholipids containing trans-fatty acid residues in high yield. These processes are radical chain reactions with relatively long chain lengths. The rate constant for the β-elimination of a thiyl radical from the adduct radical has been estimated to be 6 x 106 s-1 at ambient temperature. The cis-trans isomerization of fatty acid residues in DOPC vesicles (multilamellar vesicles and large unilamellar vesicles made by the extrusion technique) by a thiyl radical, generated from biologically relevant thiols, has also been studied in detail. The presence of 0.2 mM oxygen does not influence the effectiveness of cis-trans isomerization in both homogeneous solution and lipid vesicles. This process, which does not cause lipid degradation but permanent modification of the membrane constituents, ultimately influences the barrier properties and functions of biological membranes.
